List 2 structural divisions of nervous system and major characterists of each

Central Nervous System - CNS

Neural tracts and no CT sheaths

Peripheral Nervous System - PNS

Nerves and have CT sheaths

List 2 structural divisions of CNS and their fxns

Spinal cord

Sort info

Relay info

Basic reflex processing

Brain

Sort

Relay info

Reflex processing

Memory

Language

Homeostasis

Briefly define Peripheral Nervous System (PNS)

all neural tissue outside the CNS. It delivers sensory information to the CNS and carries motor commands to peripheral tissue and systems.

List 2 Structural divisions of PNS and major characteristic

Cranial Nerves are nerves connected to the brain.

Spinal Nervesare nerves connected to the spinal cord

List 3 functional divisions of PNS

Afferent Neuron Division

Efferent Neuron Division

Interneuron Divison

Define Afferent Neuron Division

(Sensory)

a division of PNS that brings sensory information to CNS from receptors in peripheral tissues and organs

Define Efferent Neuron Division

(Motor)

a division of PNS that carries motor commands away from CNS to muscles, glands and adipose tissue

List 2 divisions of the Efferent division

Somatic Nervous System (SNS)

Autonomic Nervous System (ANS)

What is the fxn of the Somatic Nervous System

Control skeletal muscles, both voluntary and involuntary

What is another name for involuntary muscle contraction

Reflex

What is the fxn of the Autonomic Nervous System

also called the visceral motor system, it provides automatic regulation organs and organ systems at the subconscious level

Define Interneuron Division

they are asociation neurons and are most numerous neurons in body. Nost associated with the CNS but some are autonomic ganglia. They are responsible for distribution of sensory information and the coordination of motor activity.

List 2 divisions of the ANS

Sympathetic - speeds up heart rate

Parasympathetic Division - slows down heart rate

Whats a soma?

cell body of neuron

Whats the fxn of the cell body

Houses nucleus and perikaryon

receives and processes info

Whats the fxn of the dendrites

Receive info from other neurons

Whats the axon and its fxn

its the "tail" of the neuron that is capable of spreading and electrical impulse known as an action potential

Describe hillock

the "neck" area of the neuron where the axon attaches to the soma

Describe axon collateral

collective brances that extend from the main axon

Describe axon terminal

very end of axon or telodendria aka. synaptic terminals

What is myelin made of

lipids

What is the fxn of myelin

insulate and speed the AP along the axon

What CNS neuroglial cell produces myelin

oligodendrocytes

What PNS neuroglial cell produces myelin

Schwann cells

What is a node of Ranvier and what material is not present in the node area?

the gaps in myelin on the axon. They are there for ion channels to continue electrical currents.

What structures are found in node of Ranvier

ion channels

What is saltotory propagation

myelinated fibers. AP jumps from node of Ranvier to node of Ranvier. Because it jumps, it is much faster than non-mylinated. uses less E cuz contacts less surface area

one process attached to cell body that splits into receiving and sending. found in sensory areas like skin for touch and temp

Describe bipolar neurons

2 distinct processes off the soma, one for sending and one for receiving. found in sensory areas (eyes, mouth, nose) for senses.

Describe multipolar neurons

The "common neuron". multiple dendrites and a single axon. All motor and intermeurons and some sensory neurons.

List 4 kinds of neuroglial cells in CNS

Ependymal cells

Astrocytes

Oligodendrocytes

Microglia

List the 2 kinds of neuroglial cells in PNS

Satellite cells

Schwann Cells

Define Ependymal Cells

located in space around central canal of central canal of spinal cord and in spaces of brain. Helps make cerebral spinal fluid and acts as filter and blood-brain barrier

Define Astrocytes

largest and most numerous in CNS, they maintin a stable environment for neurons, fill in damaged areas of CNS and forms scar tissue after injury

Define Oligodendrocytes

Produce myelin in the CNS and physically support and organize CNS

Define Microglia

sm glial cell that fxns as phagocytes (clean up crew)

Define Satellite cells

poduce myelin for neurons and assist in healing process in PNS

Define ganglia

cells that support nuerons

Define Schwann Cells

found in ganglia, they produce myelin for neurons in PNS as well as assist in healing

What is white matter

myelinated neuro tissue in CNS such as axons, Tracts and Nerves.

What is grey matter

non myelinated neuro tissue in CNS including somas, dendrites, some axons and are found at sites of connection processing - areas will lots of cell bodies like on the surface of the brain and in the ctr of the spinal cord

Describe the Na+ chem concentration gradient and K+ concentration gradient across cell membrane and why is it important

Important because it creates potential energy because of the differences in charges

What role does the sodium and potassium pump have in setting up, maintaining and restoring resting membrane potential?

High level of Potassium ions within a cell at rest keep a neg charge while a high level of sodium outside the cell make it a + charge thus creating a polarized neuron. It is these 2 ions that control the set up, maintaining and restoring resting membrane potential

Define leakage channels

passive channels that are always open but are ion specific. They are located on the plasma membrane

What do leakage channels have to do with cell membrane potential

They maintain the resting Resting membrane potential

What are 3 types of gated channels

chemically gated channels

mechanically gated channels

voltage gated channels

What are some things that act as keys for gated channels

NT and hormones. ACh common key

What is depolarization

Any shift from resting potential toward a more positive potential

What are 2 common ions that will depolarize a cell

Na+ or Ca+2

Define threshold stimulus

stimulus with depolarization large enough to open voltage-gated channels which initiates an action potential

What ion channels open and which close during repolarization?

Na+ channels close and K+ channels open

Define hyperpolarization

making the inside of the cell more negative than RMP

Move + ions like K+ out of cell or - ions like Cl- into cell

Describe Type A nerve fibers

lg diameter and myelinated. FAST (140m/sec). Usually deal with balance and protective reflexes

Describe Type B fibers

sm in diameter and myelinated. Not as fast as A but still (18m/sec). found for heart rate, breathing, muscles and facial

Describe Type C fibers

smallest and non-myelinated. Slowest (1m/sec). internal organ control

Describe the structure of an Electrical synapse

the pre and post synaptic membranes are locked together at gap junctions thus resulting in AP quickly and efficiently propagating from one cell to the next. Rare except in heart, some areas of brain and in the eye.

What is biggest problem with Electrical synapse

reliability

Define Chemical synapse

pre and post synaptic neurons do not touch. Space in between is called synaptic cleft

Define Synaptic delay

the time it takes signal to cross cleft and NT to bind to post synaptic cell

Define post synaptic potential

Electrical potential generated in the post-synaptic cell in response to NT. Graded potentials and can be Excitatory Post-synaptic potential (EPSP) or Inhibitory Post-synaptic Potential (IPSP)

What does Graded mean

The size of the stimulus determines the local depolarization or hyperpolarization